t4034: abstract away SHA-1-specific constants

[thirdparty/git.git] / Documentation / git-cvsimport.txt

git-cvsimport(1)
================

NAME
----
git-cvsimport - Salvage your data out of another SCM people love to hate


SYNOPSIS
--------
[verse]
'git cvsimport' [-o <branch-for-HEAD>] [-h] [-v] [-d <CVSROOT>]
	      [-A <author-conv-file>] [-p <options-for-cvsps>] [-P <file>]
	      [-C <git_repository>] [-z <fuzz>] [-i] [-k] [-u] [-s <subst>]
	      [-a] [-m] [-M <regex>] [-S <regex>] [-L <commitlimit>]
	      [-r <remote>] [-R] [<CVS_module>]


DESCRIPTION
-----------
*WARNING:* `git cvsimport` uses cvsps version 2, which is considered
deprecated; it does not work with cvsps version 3 and later.  If you are
performing a one-shot import of a CVS repository consider using
http://cvs2svn.tigris.org/cvs2git.html[cvs2git] or
http://www.catb.org/esr/cvs-fast-export/[cvs-fast-export].

Imports a CVS repository into Git. It will either create a new
repository, or incrementally import into an existing one.

Splitting the CVS log into patch sets is done by 'cvsps'.
At least version 2.1 is required.

*WARNING:* for certain situations the import leads to incorrect results.
Please see the section <<issues,ISSUES>> for further reference.

You should *never* do any work of your own on the branches that are
created by 'git cvsimport'.  By default initial import will create and populate a
"master" branch from the CVS repository's main branch which you're free
to work with; after that, you need to 'git merge' incremental imports, or
any CVS branches, yourself.  It is advisable to specify a named remote via
-r to separate and protect the incoming branches.

If you intend to set up a shared public repository that all developers can
read/write, or if you want to use linkgit:git-cvsserver[1], then you
probably want to make a bare clone of the imported repository,
and use the clone as the shared repository.
See linkgit:gitcvs-migration[7].


OPTIONS
-------
-v::
	Verbosity: let 'cvsimport' report what it is doing.

-d <CVSROOT>::
	The root of the CVS archive. May be local (a simple path) or remote;
	currently, only the :local:, :ext: and :pserver: access methods
	are supported. If not given, 'git cvsimport' will try to read it
	from `CVS/Root`. If no such file exists, it checks for the
	`CVSROOT` environment variable.

<CVS_module>::
	The CVS module you want to import. Relative to <CVSROOT>.
	If not given, 'git cvsimport' tries to read it from
	`CVS/Repository`.

-C <target-dir>::
	The Git repository to import to.  If the directory doesn't
        exist, it will be created.  Default is the current directory.

-r <remote>::
	The Git remote to import this CVS repository into.
	Moves all CVS branches into remotes/<remote>/<branch>
	akin to the way 'git clone' uses 'origin' by default.

-o <branch-for-HEAD>::
	When no remote is specified (via -r) the `HEAD` branch
	from CVS is imported to the 'origin' branch within the Git
	repository, as `HEAD` already has a special meaning for Git.
	When a remote is specified the `HEAD` branch is named
	remotes/<remote>/master mirroring 'git clone' behaviour.
	Use this option if you want to import into a different
	branch.
+
Use '-o master' for continuing an import that was initially done by
the old cvs2git tool.

-i::
	Import-only: don't perform a checkout after importing.  This option
	ensures the working directory and index remain untouched and will
	not create them if they do not exist.

-k::
	Kill keywords: will extract files with '-kk' from the CVS archive
	to avoid noisy changesets. Highly recommended, but off by default
	to preserve compatibility with early imported trees.

-u::
	Convert underscores in tag and branch names to dots.

-s <subst>::
	Substitute the character "/" in branch names with <subst>

-p <options-for-cvsps>::
	Additional options for cvsps.
	The options `-u` and '-A' are implicit and should not be used here.
+
If you need to pass multiple options, separate them with a comma.

-z <fuzz>::
	Pass the timestamp fuzz factor to cvsps, in seconds. If unset,
	cvsps defaults to 300s.

-P <cvsps-output-file>::
	Instead of calling cvsps, read the provided cvsps output file. Useful
	for debugging or when cvsps is being handled outside cvsimport.

-m::
	Attempt to detect merges based on the commit message. This option
	will enable default regexes that try to capture the source
	branch name from the commit message.

-M <regex>::
	Attempt to detect merges based on the commit message with a custom
	regex. It can be used with `-m` to enable the default regexes
	as well. You must escape forward slashes.
+
The regex must capture the source branch name in $1.
+
This option can be used several times to provide several detection regexes.

-S <regex>::
	Skip paths matching the regex.

-a::
	Import all commits, including recent ones. cvsimport by default
	skips commits that have a timestamp less than 10 minutes ago.

-L <limit>::
	Limit the number of commits imported. Workaround for cases where
	cvsimport leaks memory.

-A <author-conv-file>::
	CVS by default uses the Unix username when writing its
	commit logs. Using this option and an author-conv-file
	maps the name recorded in CVS to author name, e-mail and
	optional time zone:
+
---------
	exon=Andreas Ericsson <ae@op5.se>
	spawn=Simon Pawn <spawn@frog-pond.org> America/Chicago

---------
+
'git cvsimport' will make it appear as those authors had
their GIT_AUTHOR_NAME and GIT_AUTHOR_EMAIL set properly
all along.  If a time zone is specified, GIT_AUTHOR_DATE will
have the corresponding offset applied.
+
For convenience, this data is saved to `$GIT_DIR/cvs-authors`
each time the '-A' option is provided and read from that same
file each time 'git cvsimport' is run.
+
It is not recommended to use this feature if you intend to
export changes back to CVS again later with
'git cvsexportcommit'.

-R::
	Generate a `$GIT_DIR/cvs-revisions` file containing a mapping from CVS
	revision numbers to newly-created Git commit IDs.  The generated file
	will contain one line for each (filename, revision) pair imported;
	each line will look like
+
---------
src/widget.c 1.1 1d862f173cdc7325b6fa6d2ae1cfd61fd1b512b7
---------
+
The revision data is appended to the file if it already exists, for use when
doing incremental imports.
+
This option may be useful if you have CVS revision numbers stored in commit
messages, bug-tracking systems, email archives, and the like.

-h::
	Print a short usage message and exit.

OUTPUT
------
If `-v` is specified, the script reports what it is doing.

Otherwise, success is indicated the Unix way, i.e. by simply exiting with
a zero exit status.

[[issues]]
ISSUES
------
Problems related to timestamps:

 * If timestamps of commits in the CVS repository are not stable enough
   to be used for ordering commits changes may show up in the wrong
   order.
 * If any files were ever "cvs import"ed more than once (e.g., import of
   more than one vendor release) the HEAD contains the wrong content.
 * If the timestamp order of different files cross the revision order
   within the commit matching time window the order of commits may be
   wrong.

Problems related to branches:

 * Branches on which no commits have been made are not imported.
 * All files from the branching point are added to a branch even if
   never added in CVS.
 * This applies to files added to the source branch *after* a daughter
   branch was created: if previously no commit was made on the daughter
   branch they will erroneously be added to the daughter branch in git.

Problems related to tags:

* Multiple tags on the same revision are not imported.

If you suspect that any of these issues may apply to the repository you
want to import, consider using cvs2git:

* cvs2git (part of cvs2svn), `http://subversion.apache.org/`

GIT
---
Part of the linkgit:git[1] suite